Related papers: One constraint to kill them all?
As is well known, $B^0_{d,s}$--$\bar B^0_{d,s}$ mixing offers a profound probe into the effects of physics beyond the Standard Model. The data obtained at the $e^+e^-$ $B$ factories have already provided valuable insights into the…
The discrepancies between $b\to s\ell^+\ell^-$ data and the corresponding Standard Model predictions point to the existence of new physics with a significance at the $5\sigma$ level. While previously a lepton flavour universality violating…
We review recent results for B_d and B_s mixing parameters using MILC N_f=2+1 lattices, NRQCD b-quarks and AsqTad light quarks. Latest numbers for decay constants f_B and f_{B_s} are also presented. Combining our lattice results with…
While the $S_3$ scalar leptoquark presents a possible tree-level explanation of the $b \to s \ell \ell$ flavour anomalies, it suffers from two conceptual problems which are often disregarded by model-builders. Firstly, the quantum numbers…
$Z^\prime$ models belong to the ones that can most easily explain the anomalies in $b\to s \mu^+\mu^-$ transitions. However, such an explanation by a single $Z^\prime$ gauge boson, as done in the literature, is severly constrained by the…
We consider the effects of a non-vanishing strange-quark mass in the determination of the full basis of dimension six matrix elements for $B_{s}$ mixing, in particular we get for the ratio of the $V-A$ Bag parameter in the $B_s$ and $B_d$…
$B$ anomalies play a prominent role in Beyond the Standard Model (BSM) physics searches. In particular, the long standing tension between the inclusive and the exclusive determinations of the CKM matrix element $|V_{cb}|$ and the current…
One of the fundamental predictions of the Standard Model is Lepton Flavour Universality. Any deviation from this prediction would indicate the existence of physics beyond the Standard Model. Recent LHCb measurements present a pattern of…
Combined analysis of recent measured $\bs$ mixing and $B \to X_s \gamma$ decays provides constraints on the anomalous $\bar{t}sW$ couplings. We discuss the perspectives to examine the anomalous $\bar{t}sW$ couplings through CKM-suppressed $…
New physics models that increase the decay rate of $B_s \to \tau^+ \tau^-$ contribute to the absorptive part of $B_s$--$\bar{B}_s$ mixing, and may enhance $\Delta\Gamma_s$ all the way up to its current experimental bound. In particular, the…
We scrutinize the recently further strengthened hints for new physics in semileptonic $B$-meson decays, focusing on the 'clean' ratios of branching fractions $R_K$ and $R_{K^\ast}$ and examining to which pattern of new effects they point…
In recent years, significant experimental indications that point towards Lepton Flavour Universality violating effects in B-decays, involving $b \to c \tau \nu$ and $b \to s \ell^+ \ell^-$ have been accumulated. A possible New Physics…
During the last years, the ALPHA collaboration has been developing and implementing a method based on Heavy Quark Effective Theory (HQET) to compute B-mesons observables through lattice simulations. Thanks to a non-perturbative matching to…
We study the implications of minimal flavor violating low energy supersymmetry scenarios for the search of new physics in the B and Higgs sectors at the Tevatron collider and the LHC. We show that the already stringent Tevatron bound on the…
Several measurements of B-meson decay observables show deviations from Standard Model (SM) predictions, some of them hinting at violation of lepton flavour universality (LFU). I discusses how the anomalies in rare B decays can be explained…
Significant deviations from the Standard Model are observed in semileptonic charged and neutral-current B-decays, the muon magnetic moment, and the extraction of the Cabibbo angle. We propose that these deviations point towards a coherent…
The couplings of the fermions to the Z boson are of great importance in establishing the validity of the Standard Model and in looking for physics beyond it. The couplings of the b-quark to the Z boson have been the subject of much…
Recently two hints for new physics have emerged: The B_s mixing phase phi_s and the rate of D_s -> (mu,tau) nu exposing a discrepancy of \sim 3 sigma and 3.8 sigma deviation from the Standard Model respectively. Moreover the difference of…
LHCb found hints for physics beyond the standard model in $B\to K^*\mu^+\mu^-$, $B\to K^*\mu^+\mu^-/B\to K^*e^+e^-$ and $B_s\to\phi\mu^+\mu^-$. In addition, the BABAR results for $B\to D^{(*)}\tau\nu$ and the CMS excess in…
We attempt to explain recent anomalies in semileptonic $B$ decays at LHCb via a composite Higgs model, in which both the Higgs and an $SU(2)_L$-triplet leptoquark arise as pseudo-Goldstone bosons of the strong dynamics. Fermion masses are…